A vivid nodule of precious opal from the Semien Wollo Mountains of northwestern Ethiopia — one of the most exciting gem discoveries of the last two decades. Welo (Wollo) opal forms in silica-rich veins within volcanic rhyolite and ignimbrite, a fundamentally different origin from the sedimentary opals of Australia, and was only recognized commercially in 2008.
This particular specimen is non-hydrophane — a less common and generally more stable variety of Welo material. Unlike the majority of Ethiopian opal, which readily absorbs water and shifts in clarity and color as a result, non-hydrophane Welo opal holds its water content and structure and doesn't undergo that transformation, making it more forgiving to handle, display, and wear without the risk of crazing or cracking that can come with repeated wetting and drying cycles in the hydrophane form.
Prized for exceptionally bright, saturated play-of-color, this piece shows flashes of [red/orange/green/blue — describe what's actually present] set against a translucent to milky body — with the added durability advantage that comes with its non-hydrophane structure.
Material: Precious opal (non-hydrophane), rhyolite-hosted
Locality: Wollo Province, Ethiopia
Hardness: 5.5–6.5 (Mohs)
